Fountain-type marking device



' April 6, 1943.

J. W. WIRFEL FOUNTAIN-TYPE MARKING DEVICE Filed Jan. 16, 1941 INVENTQYR Patented Apr. 6, 1943 UNITED STATES PATENT 'OFFICE 2,316,049 FOUNTAINLTYPE MARKING DEVICE James W. Wirfel, Ridgewood, Y. Application January 16, 1941, Serial No. 374,673

4 Claims.

- This invention relates to marking devices, and more particularly to such devices of the fountai-n type.

He-retofore numerous fountain-type markers have been proposed employing a stamping surface and a reservoir for the liquid or ink. However, in the case of devices which are intended to imprint a speci'al design, letter, numeral or the 'like on a porous receiving surface such as pa-per, considerable difficulty has been encountered in controlling the proper amount of ink to be applied to the marking pad. Furthermore in such devices it is necessary that some means, usually in the form of a valve, be employed to prevent the'flow of ink tothe marking pad when the device is not in use. On the other hand, it is important that the ink be practically instantly available to the pad when it is to be used. One suggested solution for such difficulty is to provide avalve between the reservoir and pad. 'Ilh'e valve member being normally held against its seat by a spring. I have found that with such an arrangement, because of the fact that the spring must be strong enough to retain the valve against its seat, in order to remove it so as to allow the link to flow to the pad, considerable force must be applied and even then the valve is opened only for a very small fraction of a second. In such arrangements therefore, the flow of ink'to the --actual external marking surface of the pad is effected substantially entirely by capillary action or absorption in the pad itself.

Accordingly, it is a principal object of this invention to provide a novel form of fountain- Ltype marker employing a freely supported valve member.

A feature of the invention relates to a fountain-type marker wherein a free ball is used to perform the double function of a closure valve and by its inertia to apply an ejection impulse to force the ink from the fountain or reservoir to the pad.

A further feature relates to the novel organization, arrangement and relative location and proportion of parts which constitute a cheap, simple and eiiicient marking or stamping device wherein the amount of ink applied to the stamping pad can be accurately controlled.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions and appended claims.

In the drawing which represents one preferred embodiment of the invention,

tube in a Iiquid-tight manner.

extends slightly below the edge of lip 8.

Fig. 1 is a vertical sectional view of a marking device according to the invention.

Fig. 2 is an outside elevational view of the device with the removable cover in place.

Referring to the drawing, the device comprises a tubular member I which may be made of any suitable material such as metal, glass, Bakelite, or any other of the well-known plastics. The tube 1 is open-ended at the top so as to facilitate filling it with ink or other suitable marking liquid. After the proper quantity of ink has been poured into the tube, the upper end is closed by a screw-threaded cap 2, and preferably a sealing disc 3 of rubber, lead or other similar material is provided between the cap and the end of the tube. The cap 2 is tightened sufliciently to prevent the pressure of the outside air exerting any force on the top surface of the liquid column, so that normally no liquid'can flow out of the lower end of the tube even though the valve member '1 is not actually seated against its valve seat. a

The lower end of tube I has interiorly thereof a ioulder 5 which may be formed integrally the tube or it may be a separate ring or bushing tightly fitted into the lower end of the The shoulder 5 ha central restricted or narrow passage 6 t hiioi'ig h which the ink 4 is adapted to be forced by the weight of the ball 1 when the latter drops by gravity into place as will be described here- :inbelow. The lower end 'of tube 1 has a tapered lip portion 8 to receive a porous pad 3 of felt,

sponge rubber or other suitable material. Pref- 'erably, pad 9 is held in the end of tube A by fric 'tion so that it can be readily removed for replacement or cleaning and as will be seen from Fig. 1 the actual stamping surface of the pad A suitable protective cover I!) may be held in place on the tube by friction or it may be threaded on to the ,tube in any well-known manner. However, "cover l-S! isprovided with a perforation H so that if it is pulled on very rapidly no suction is created which would otherwise tend to suck ink from pad 9.

As will be seen, the shoulder 5 has in alignment with passage 6, a hemispherical valve seat con forming to the ball I, so that when the device is in an upright position as shown in Fi 1, the ball I is held solely by gravity against the seat and prevents any accidental leakage of liquid. However, as pointed out above, since the upper end of tube l is sealed against atmospheric pressure, there is almost no chance of liquid flowing out of the tube even though the ball 1 is not actually seated against the valve seat. I have found that by making the passage 6 relatively narrow, and since the cover 3 is sealed against atmospheric pressure in order to cause liquid to flow to the pad 9, it is necessary to force it through the passage 6. By properly designing the Width of passage 6 and taking into account the surface tension of the liquid 4 at the lower end of the passage, no ink can normally flow from the passage. It will be noted that there is a slightly tapered space between the lower end of passage 6 and the surface of pad 8 so that normally it requires more than the mere weight of the liquid column to wet the pad. I have taken advantage of this arrangement to make sure that the pad is not moistened except when it is to be used. In order to control the wetting of the pad, I have discovered that the ball 1 must be entirely free within the tube l. The wetting of the pad is therefore effected simply by turning the device upside down allowing the ball I to fall by gravity towards the cap 3. The device is then restored to its upright position and the ball again falls by gravity to the position shown in Fig. 1. During the downward descent of the baIL-because of its size, mass and inertia, it forces the liquid through the passage 6. This impulse is accentuated as the ball approaches the seat because of the entrapped liquid at that region, so that the ball acts in the nature of a piston applying an impulse to the liquid in passage 6 of sufficient magnitude to overcome the pressure of the atmosphere and the surface tension of the liquid thus causing it to flow to the pad 9. I have also found that if the ball 1 is restrained, for example by means of a spring of sufficient tension to hold it against the valve seat, that very little if any liquid can be ejected.

Instead of using a ball-shaped valve member and a hemispherical seat, a flat seat valve may be used. Such an arrangement is shown in Fig. 3 wherein the parts corresponding to those of Fig. I bear the same designation numerals. In this embodiment the valve member has a flat undersurface which engages the flat surface of shoulder 5. The valve member is formed with a substantially cylindrical portion l3 terminating in a tapered portion M. The portion I3 is smaller in diameter than the internal diameter of tube I so as to prevent binding when the valve member drops but is large enough to provide a piston-like action. The length of the cylindrical section I3 is preferably such that with respect to the internal diameter of tube I, the valve member is incapable of turning over or binding diagonally within the The tapered portion i4 expedites the dropping of the valve member when the device is turned upside down by having a somewhat streamline effect in passing through the liquid In another modification, the ball valve l- (Fig. 4) may be provided with a peripheral circular flange l so as to accentuate the piston-like action of the valve member when it drops by gravity to force the liquid through passage 6. In all of the foregoing embodiments preferably the freely movable valve member 1 is made of a relatively heavy metal which is non-corrosive with respect to the ink, for example stainless steel or the like may be used for that purpose.

While one particular structure and embodiment of the invention has been illustrated in the drawing, it will be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

What I claim is:

1. A device of the character described comprising, a tubular ink container having one end adapted to be sealed substantially entirely airtight by a removable cap for filling, a constricted ink passage at the other end of said container, said passage having at its interior end an enlarged portion to serve as a valve seat, an ink pad carried at said other end of the container, a freely movable weighted valve member within said container and arranged to seat against said valve seat, a shoulder at the outer end of said constricted passage for spacing said pad from said constricted passage whereby said pad can be moistened only in response to an impulse from said valve member for forcing ink through and out of said constricted passage which impulse is produced by the free falling of said valve against said seat, the dimensions of said passage being such that ink cannot run therefrom on to said pad even though said valve member is off its seat except in response to said impulse.

2. A device of the character described comprising a tubular ink container having one end adapted to be sealed substantially entirely airtight by a removable cap for filling, a constricted cylindrical ink passage at the other end of said container, a flared opening at the interior end of said passage, a flared opening at the exterior end of said passage, said interior flared opening serving as a valve seat, an ink pad carried on the said other end of the container and in spaced relation to the exterior end of said constricted passage, and a freely movable weighted valve member inside said container for delivering an ink expulsion impulse to the ink in said constricted passage to overcome the surface tension of the ink at the outer end of said passage whereby ink is forced outwardly from said passage and said pad is moistened only in response to said impulse, the dimensions of said passage being such that ink cannot run therefrom on to said pad even through said valve member is ofi its seat except in response to said impulse.

3. A device according to claim 2 in which said valve member is of a much smaller diameter than the interior diameter of the container and is provided with a peripheral flange to increase the expulsion force on the ink in said passage.

4. A device according to claim 2 in which the valve member has a fiat valve seating surface and a stream-lined tail portion. I

JAMES W. WIRFELL 

